A variety of products are marketed to improve water retention of soils. They include gels, beads or other compounds based on petroleum or oil derivatives. These products are not only based on non-renewable resources but also require special handling and application procedures since they contain chemical agents that can be hazardous if long term exposure or mishandling occurs during its storage or application. Most of these products are not suitable for large farms or forest areas due to their high cost. Even if their cost is reduced through more efficient processes or subsidies, many of the existing products contain chemical agents that make them non-suitable or not recommended for use in some crops. Existing products in this category use expensive, non-renewable raw materials such as petroleum, or chemical compounds that make them hazardous for use in farming land or for human consumption crops.
There exist also organic materials that are used to aid in water retention on soils. Prominent in this category are compost, mulch and other mineral-based products.
Compost is obtained from the decomposition process of organic waste assisted by waste-digesting worms that accelerate the process of decomposition. Worms accelerate this process creating an organic mass that has some water retention capabilities. In some regions in the southwest United States, compost is used as an aid in the maintenance of golf courses. However, the production cycle for compost is extremely long, the production of a metric ton of compost requires months of decomposition of organic material and it is a process that cannot be industrialized easily. This makes the cost of the compost increase and the production volumes shrink. Even though compost is an organic and renewable alternative, the limitations in production capacity and the elevated cost related to its production importantly hamper its viability as an option to reduce water consumption for large arid regions that have a strong population growth and a growing demand for water.
Mulch is usually obtained from bark, compost, grass clippings or straw and is spread or laid over the surface of the soil as a covering. It is used to retain moisture in the soil and suppress weeds. It also keeps the soil cool and makes the garden bed look more attractive. Organic mulches also help improve the soil's fertility, as they decompose. Compost and mulch have a low percentage of water retention for their weight or volume. Both materials also lose accumulated moisture at a high rate.